Nikon D3100 display delay in Manual

KazzyUK

Hi, I am a complete newbie to this, so please bear with me.

I recently bought a Nikon D3100 and with the current shorter days, nighttime photography is something I've been trying. My problem is that when I take a longer exposure (in Manual), the camera takes almost as long as the shutter is open before it displays it on the LCD screen, making it impossible to use the camera until it has displayed the picture. This is fine if it's 5 seconds, but I've been playing with a remote and doing 1-5 minutes. I'm beginning to lose the will to live (as well as missed shots) while I wait. My friend has a D5100 and his pops them up almost instantly. Is this normal?

bruto

Not being in the habit of long exposures, I tried this with a D3200. I am sorry to say it seems to be normal, though I don't know why. If you take a ten second exposure it takes 10 seconds to save. If you take a 30 second exposure, it takes 30 seconds to save. The time is the same in RAW as it is in small low quality JPG.

I do not know why this is so, but it appears to be. I guess the D5100 and others use different software. When I get the chance I'll try this with my wife's D7100 and see how it behaves.

Edit to add: I just tried it with a D7100, and a 30 second exposure finished saving in a few seconds. Definitely not the same from model to model.

Edit further to add: this occurs not just in manual mode, but S and A modes too if you force a very slow shutter speed.

It also occurred to me to be sure it does not depend either on auto white balance or active D-lighting. It does not. I'm still experimenting.

FINAL EDIT TO ADD: It is the noise reduction. Turn off noise reduction, and all long exposures take a few seconds to save. I suppose more advanced cameras have a quicker computer for this function, but you should check with your friend who has the D5100 to see if his NR is turned off.

bruto

I did some more research, and it appears that this feature is indeed a feature, and that it does occur in other models. Here is a link that explains it (you must read down a way)

http://www.astropix.com/HTML/I_ASTROP/SETTINGS.HTM

The time is doubled, because the camera actually takes a second "dark frame" exposure with the shutter closed, gathering no image but just thermal noise, which it then subtracts from the image.

KazzyUK

Thank you so much! I updated the firmware, bought a higher class SD card and in the end, it was turning the noise reduction off that sorted it. I will no longer be grinding my teeth as I watch planes go overhead and wait for my camera to load.